package jwlee.testclassrelation;

public class TestExtends {
	public void f() {
		DrivingUtilities du;
		FourWheeler fw;
		Truck myTruck = new Truck();
		du = (DrivingUtilities) myTruck;
		fw = new Crane();
		//fw = du;
	}

	interface DrivingUtilities {
	}

	class FourWheeler implements DrivingUtilities {
	}

	class Car extends FourWheeler {
	}

	class Truck extends FourWheeler {
	}

	class Bus extends FourWheeler {
	}

	class Crane extends FourWheeler {
	}
	
}